解决web 中Tab键、Backspace键、Enter键

在页面需要控制位置加入onkeydown事件调用onkeydown = “return bodyvalidate(event,'All')”方法，return 返回条件你的事件是否成功。
配合还得用onload事件聚焦此位置onload=“this.focus();”
Tab ：keyCode == 9。Enter：keyCode == 13。Backspace：keyCode == 8。

    function bodyvalidate(event,flag,array){
        var e =   (event)?event:window.event;
        //alert(e.srcElement.tagName);
        //alert(e.target.parentNode.tagName);
        if(flag == "TabEnter"){
            if(e.keyCode == 9){
                     return false;
             }
            if(!window.document.all){//alert(e.keyCode);
                if(e.keyCode==13 && e.target.tagName!='TEXTAREA'){
                    return false;
                 }
            }else{
                if(e.keyCode==13 && e.srcElement.tagName!='TEXTAREA'){
                    return false;
                }
            }
        }else if(flag == "Backspace"){
            if(e.keyCode =={
                return false;
            }
        }else if(flag == "All"){
            if(e.keyCode == 9){
                     return false;
             }
            if(e.keyCode =={
                    return false;
            }
            if(!window.document.all){//alert(e.keyCode);         
                if(e.keyCode==13 && e.target.tagName!='TEXTAREA'){
                    return false;
                 }
            }else{
                if(e.keyCode==13 && e.srcElement.tagName!='TEXTAREA'){
                    return false;
                }
            }
        }     
    }

修改：

    function bodyvalidate(event,flag,array){
        var e =   (event)?event:window.event;
        //alert(e.srcElement.tagName);
        //alert(e.target.parentNode.tagName);
        if(flag == "TabEnter"){
          
            if(!window.document.all){//alert(e.keyCode);
                 if(e.keyCode == 9 && (e.target.tagName!='INPUT' && e.target.tagName!='SELECT')){
                     return false;
                 }
                if(e.keyCode==13 && e.target.tagName!='TEXTAREA'){
                    return false;
                 }
            }else{
                if(e.keyCode == 9 && (e.srcElement.tagName!='INPUT' && e.srcElement.tagName!='SELECT')){
                     return false;
             }
                if(e.keyCode==13 && e.srcElement.tagName!='TEXTAREA'){
                    return false;
                }
            }
        }else if(flag == "Backspace"){
            if(e.keyCode =={
                return false;
            }
        }else if(flag == "All"){
            if(e.keyCode == 9){
                     return false;
             }
            if(e.keyCode =={
                    return false;
            }
            if(!window.document.all){//alert(e.keyCode);         
                if(e.keyCode==13 && e.target.tagName!='TEXTAREA'){
                    return false;
                 }
            }else{
                if(e.keyCode==13 && e.srcElement.tagName!='TEXTAREA'){
                    return false;
                }
            }
        }     
    }